No, 2x6970 isn't good value for money, and if there are issues with 6950 crossfire (which I doubt) then there are issues with 6970 crossfire too, they're very similar chips. In addition it's possible to BIOS flash some 6950's to unlock extra computing power, and they're pretty overclockable as well; this brings them near the performance of a 6970 but cost much less. You should just go with 6950 2gb crossfire, that's what I recommend and it's final
1000W is overkill for your setup. You're better off with a 850W PSU. If you don't unlock and overclock the 6950's, you're perfectly fine with 750W. I don't recommend Cooler Master if there are alternatives such as the ones I've already listed:
If you really can't find any of the above at a reasonable price, then a CM Silent Pro Gold 800W is a good choice.